I've seen that recommended to get rid of PS residue and heard that it also leaves a short-term shine on the fondant. Not an issue for me--I roll on vinyl with a swipe of Crisco (no residue, plenty of shine).

Some people mix Luster Dusts or Pearl Dust with Vodka and spray it on their cakes. I think it works better with an air gun... To get powdered sugar off of fondant just rub with a little shortening, it will be absorbed, and the shine will go away in a few hours...

Wow...that is so weird... It cut off half of what I wrote... I was also saying that I think it works better with an air gun... And that you can get rid of powdered sugar on fondant by just rubbing it gently with a small amount of shortening... It will absorb into the cake and the "shiny" will go away within a few hours...